As is known in the art, radar sensors for motor vehicles (vehicular radar sensors) are generally used for detecting target objects in the surroundings of a “host vehicle” (i.e. a vehicle in which the radar sensor is disposed) and may assist the driver in many aspects of operating the motor vehicle. To detect target objects, a radar sensor transmits radio frequency (RF) signals (electromagnetic waves) which impinge upon and may be reflected from one or more target objects. The radar sensor receives at least portions of the so-reflected signals (sometimes referred to as “echo signals”). From such received signals, a collection of detection points is acquired and processed to identify, and determine information relating to, one or more target objects.
Radar sensors may, for example, determine both speed of a target object relative to the host vehicle as well as a so-called “target angle,” i.e. an angle between an imaginary connecting line the target object and a reference line. The reference line may, for example, correspond to a longitudinal axis of the host vehicle. Using a radar sensor, it is therefore possible to determine a current position of the target object relative to the host vehicle. It is also possible to track a target object located in a sensing region of the radar sensor i.e. the relative position of the target object can be determined continuously over a multiplicity of measurement cycles of the radar sensor.
As is also known, detection of broadside or “hovering” vehicles (that is vehicles traveling substantially adjacent to the host vehicle and at approximately a same speed as the host vehicle) as well as detection of static objects (i.e. non-moving objects) present certain difficulties for conventional radar sensors which results in a radar sensor providing an undesirable number of false alerts or late alerts for such objects.